Nagoya Journal of Medical Science

Population study was made on Austropeplea ollula (Gould), the snail intermediate host of avian schistosomes which caused paddy field dermatitis. from the viewpoint of successive changes in the size of the snails in the field in relation to the occurrence of the dermatitis. The growth of the snail host was observed by analyzing the shell-size distributions ofsummer and overwintering populations. Young snails born in autumn composed the overwintering population in rice stubbles, and appeared on the soil surface in spring season after irrigation water was introduced into the paddy fields. During the first breeding season in early summer, the snail population on the soil surface consisted of two different size-groups, i.e., a few large snails which overwintered in rice stubbles and a majority of small ones produced by the overwintered snails. During the period from May to October, breeding of the snails was observed twice, first in early summer and again in autumn. The large snails, which were more likely to harbour the cercariae, were found in May-June, August and October, but their density was low in August and October due to draining of the paddy field as a step in rice farming. In consideration of these circumstances, the large snails found in May-June were suggested to be responsible for the occurrence of the dermatitis. Accordingly, snail control measures should focus on the large snails which overwinter in paddy fields.

Computed and frontal tomograms were taken of 20 patients with carcinoma of the maxillary sinus and were evaluated in order to compare the diagnostic accuracy of both procedures. Tomographic accuracy, sensitivity, and specificity in diagnosing tumor densities and bone defects were evaluated by comparing the tomogram's findings with the surgical results. The diagnostic accuracy of CT in diagnosing tumor densities was greater than that of frontal tomography. The value of both CT and frontal tomography in diagnosing bone defects was encouraging. but not conclusive. The future contributions of macrotomography and digital radiography in diagnosing carcinoma of the maxillary sinuses are the subjects ofdiscussion in this paper.

A phantom simulating the transverse section of the maxillary sinuses was constructed for experimentation with various CTscanners to study the following: (1) the occasional inability to image the very thin posterior-lateral walls which have no real bone defects, and (2) to verify whether or not the bony walls surrounding the maxillary sinuses are actually as thick as they appear on CT. The phantom was made of an acrylic cylinder containing three cavities simulating the maxillary sinuses and the nasal cavity and filled with water. The walls, made of thin aluminum and acrylic plates and placed between water and air, disappeared in some CT images. The thickness ofthe walls calculated from CT values was greater than the true thickness imaged by each CT scanner. The author stresses that in CT images, either experimentally or c!inically, thin bony walls placed between water and air or fat tend to disappear, and that bony walls tend to appear thicker than their true thickenss.

Tubular dysfunctions of renal homograft cases have been reported from several aspects. However, chronic hypophosphatemia of the kidney transplant recipient is a relatively new topic. It is encountered frequently and is considered to be very important in differential diagnosis of persistent hyperparathyroidism.
We studied this chronic hypophosphatemia in our intrafamiliar renal homograft recipients.

The clinical effect of 1α-OH-D₃, a synthetic analogue of the active form of Vitamin D, was investigated in hemodialized patients. The administration of 1α-OH-D₃ with supplementary calcium therapy (at doses equivalent to 520 mg of elemental calcium per day) produced a significant biochemical improvement characterized by an increase in serum calcium concentration. lowered serum inorganic phosphate content and diminution of(Ca)X(Pi), without any appreciable increase in parathyroid hormone (PTH). There was actually no patient showing exacerbation in skeletal X-ray findings following the treatment. The reversal from a lowered serum calcium level might be largely ascribable to the improvement of the alimentary balance of calcium. Also. the decrease in serum inorganic phosphate value might have been brought about by the suppression of phosphorus absorption by supplementary calcium lactate administraion. by phosphorus deposition in bones, and by suppression of bone resorption by PTH. It was found that a calcium concentration of 3.5 mEq / L approx. in the dialysate was adequate for periodic hemodialysis. The data indicated the effectiveness of the administration of 1α-OH-D³with calcium supplementation for the prevention and treatment of renal osteodystrophy in the maintenance of hemodialized patients.

To explore the epidemiological features of aplastic anemia, the mortality statistics (1958-1978) in Japan were examined by age and sex. Mortality trends by age were fitted by the regression curves derived from Akaike Information Criteria Method and correlated to the trend'in annual per capita production amounts of chloramphenicol (CP), taking into consideration the time-lag between the production of CP and the aplastic anemia deaths. A gradual decrease in age-specific death rates was apparent from 1960 onwards in males aged less than 45 years. In males aged 45 years and over, the year in which the mortality started to decrease apparentiy shifted to much more recent years with advancing age groups. Quite similar mortality trends by age were observed in females, though the year in which the mortality began to decrease shifted more quickly to recent years in females than in males. Annual per capital production amount ofCP had a negative correlation in the younger age groups, particularly in males, but a significantly positive correlation in the advanced aged population, though the largest correlation coefficients were obtained with different time-lags in different age groups. The time-series analysis suggested that CP appeared to be hazardous to the aged population, but this was not fully evidenced by the present analysis.

We asked if cryopreservation of human peripheral blood lymphoid cells (PBL) could maintain their function to generate cytotoxic activity against various antigens in vitro. Cells to be frozen were suspended in RPMI 1640 medium supplemented with 10% dimetylsulfoxide and 10% fetal calf serum at a concentration of 1 x 10⁷ cells per ml. One and a half ml of this cell solution per polystyrene vial were frozen in an automated programmed freezer at a cooling rate of -1°C per minute. When used for assays, cells were recovered by rapidly thawing the cell solution in the vials. The ability of thus cryopreserved PBL to generate lymphocyte cytotoxicity was compared to that of fresh PBL from the same individuals. The micromethod of in vitro sensitization was used to generate and measure lymphocyte cytotoxicity in a single 96-well plate. Reactivities to alloantigens were examined in the PBL from 6 individuals and reactivities to Epstein-Barr (E-B) virus-transformed autologous lymphocytes were tested in 4 independent experiments using the PBL from two individuals. In addition, PBL reactivity to autologous leukemia cells was more precisely analysed in one patient with acute myelogenous leukemia. The cytotoxic activities of human PBL directed against alloantigens, E-B virus-transformed autologous lymphocytes, and autologous leukemia cells were satisfactorily recovered after cryopreservation. This encourages the idea to apply this procedure in further analysis of cell-mediated immune reactions in various disease conditions. It may also raise the possibility of producing immune lymphocytes cytotoxic to autologous leukemia cells that could be therapeutically usable for leukemia patients.